Railway lines are generally made of high carbon steel as it is considered to be a suitably durable material. As some railway lines endure extreme weather environments that can rapidly expand or compress lines along with heavy axle loadings, even these high carbon steel lines suffer the risk of cracking, buckling and joint failures from time to time. The consequences of track failure can lead to catastrophic derailments leading to loss of life and damage to property. Therefore, the integrity of railway lines is considered to be essential for the safe carriage of persons and property across countries.
The repairing of cracks and defective or failed joints in railway lines poses a major problem for railway companies. One method of repairing a failed line is to cut a section of line on either side of the defective area, thus requiring welding two joints when inserting the replacement section of railway line into the track. This type of repair work is time consuming and can result in potentially weak and defective weld joints if the work is not carried out properly.
It has been a challenge to maintain the integrity of railway lines in recent years, particularly when lines are subjected to various stresses and strains imposed from trains having a heavy axle loading. The techniques for joining and rejoining sections of railway line have come under intense focus and pressure in recent years as a result of rail and weld failures, and concerns over the reliability of track repairs is being further compounded by the heavier loads trains are exerting on railway lines.
One way of repairing a railway line is by applying an aluminothermic or thermite type welding process. However, these thermite type weld joints can result in a lower strength weld compared with other methods and there is a perceived higher risk of weld failure with this type of process. These failures can be caused by sub-standard welding and due to the fact the such welds can be difficult to check for integrity and thus it is not uncommon for such welds, in some instances, to be defective. However, this form of welding a railway line does have its desirable properties, and the present invention seeks to improve the integrity of such welds.
It is a non-limiting object of the invention to provide an improved thermite weld process for joining ends of a railway line which overcomes at least some of the abovementioned problems, or at least to provide the public with a useful choice.